Long-term residential exposure to air pollution and Hodgkin lymphoma risk among adults in Denmark: a population-based case-control study

Abstract

Purpose: The etiology of Hodgkin lymphoma (HL) is obscure. Research on air pollution and risk of HL provides inconsistent results. We aimed to investigate the association between long-term residential exposure to air pollution and risk of adult Hodgkin lymphoma in Denmark.

Methods: We performed a nationwide register-based case-control study, including all (n = 2,681) Hodgkin lymphoma cases registered in the nationwide Danish Cancer Registry between 1989 and 2014. We randomly selected 8,853 age- and sex-matched controls from the entire Danish population using the Civil Registration System, and identified 20-year residential address history for all cases and controls. We modeled outdoor air pollution concentrations at all these addresses using the high-resolution multiscale air pollution model system DEHM/UBM/AirGIS. We used conditional logistic regression to estimate odds ratios adjusted for individual and neighborhood level sociodemographic variables.

Results: There was no association between 1, 5, 10, and 20 years' time-weighted average exposure to fine particles (PM_2.5), O₃, SO_2, NO_2, or the PM_2.5 constituents OC, NH₄, NO₃, and SO₄ and risk of Hodgkin lymphoma.

Conclusion: Residential exposure to ambient air pollution does not seem to increase the risk of developing Hodgkin lymphoma.

Keywords: Air pollution; Case–control; Hodgkin lymphoma; Long-term exposure.